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Prescribing Obesity Medications
Drug-Nutrient Interactions
Orlistat
• Orlistat inhibits intestinal fat absorption and can reduce absorption
of fat-soluble vitamins A,D,E, and K. To ensure suff icient intake,
patients should take a standard multivitamin administered at least
two hours apart f rom orlistat.
Topiramate
• Topiramate is a carbonic anhydrase inhibitor that can lead to non-
anion gap metabolic acidosis and hypokalemia. Potassium and
serum bicarbonate replacement may be necessary.
Phentermine
• Caffeine has the potential to amplify the stimulant effects of
phentermine.
GLP-1 RAs
• GLP-1 RAs can reduce gastric emptying. A high-fat meal can
also decrease gastric emptying, potentially leading to nausea or
abdominal discomfort when combined with a GLP-1 RA.
The majority of individuals tend to regain weight upon
discontinuation of obesity medications. Therefore, long-term
therapy is advised.
FDA-Approved Obesity Medication — Adult Indications
➤ Indicated in combination with a reduced-calorie diet and
increased physical activity to reduce excess body weight and
maintain weight reduction long term.
➤ For adults with obesity, or adults with overweight in the presence
of at least one weight-related comorbid condition.
Principles of Obesity Medications
➤ Obesity medications facilitate varying degrees of weight reduction
over differing durations in individuals with overweight or obesity.
➤ The average total body weight loss varies from 5% to 21%, with
certain individuals experiencing losses outside this range.
➤ Some individuals do not experience weight loss with obesity
medications.
➤ If weight loss of at least 5% is not attained within 12 to 16 weeks
of therapy at the maximum tolerated dose, consideration of an
alternative obesity medication is warranted.
